awk 's=$1{for($0=1e3" 900 500 400 100 90 50 40 10 9 5 4 1 M CM D CD C XC L XL X IX V IV I";k=5e3>j=++i;)for(t=_;j;)j<$k?++k:j-=A[t=t$(k+13)]=$k}$0=!!A[s]_'